Weft thread holding and cutting device for looms

ABSTRACT

The invention relates to a weft thread holding and cutting device for looms for weaving fabric without a shuttle, that is, for looms in which the weft thread is supplied by lateral spools located externally to the loom, the weft thread being drawn through the shed by a projectile provided with pincer hooks at its ends and according to the particular feature of the invention, the weft thread holding and cutting device for looms for weaving fabric without a shuttle comprises two cutting blades for cutting the weft thread and two means for gripping the end of the cut weft thread, these two blades, on one hand, and these two means on the other, being movable relatively, which device is characterized in that the two gripping means comprise gripping surfaces cooperating with one another to hold the weft thread, these two surfaces being movable parallel to the trajectory of the weft thread in the loom.

United States Patent [191 Palencher WEFT THREAD HOLDING AND CUTTING DEVICE FOR LOOMS Inventor: Jacques Palencher, Troyes, France Societe dite Lebocey Industries, Troyes, France US. Cl. 139/122 R, 139/302 Int. Cl D03d 49/70 Field of Search 139/122, 125, 263-268,

Assignee:

Primary Examiner-Henry S. .Iaudon Attorney, Agent, or Firm-Jones, Thomas & Askew [57] ABSTRACT The invention relates to a weft thread holding and cutn fi i eifetlq ms f9! wsa fabzisn tbo ta shuttle, that is, for looms in which the weft thread is supplied by lateral spools located externally to the loom, the weft thread being drawn through the shed by a projectile provided with pincer hooks at its ends and according to the particular feature of the invention, the weft thread holding and cutting device for looms for weaving fabric without a shuttle comprises two cutting blades for cutting the weft thread and two means for gripping the end of the'cut weft thread, these two blades, on one hand, and these two means on the other, being movable relatively, which device is characterized in that the two gripping means comprise gripping surfaces cooperating with one another to hold the weft thread, these two surfaces being movable parallel to the trajectory of the weft thread in the loom.

4 Claims, 7 Drawing Figures PAIENIEDEICIZSIBN- 3844316 minor-4 FIG.1

WEFT THREAD HOLDING AND CUTTING DEVICE FOR LOOMS The invention relates to a weft thread holding and cutting device for looms for weaving fabric without a shuttle, that is, for looms in which the weft thread is supplied by lateral spools located externally to the loom, the weft thread being drawn through the shed by a projectile provided with pincer hooks at its ends.

The invention is characterized in that the weft thread holding and cutting device for looms for weaving fabric without shuttle comprises two cutting blades for cutting the weft thread and two means for gripping the end of the cut weft thread, these two blades, on one hand, and these two means, on the other, being movable relatively, which device is characterized in that the two gripping means comprise gripping surfaces cooperating with one another to hold the weft thread, these two surfaces being movable parallel to the trajectory of the weft thread in the loom.

According to another characteristic feature of the invention, the gripping surfaces comprise additional deformations.

According to yet another characteristic feature of the invention, one of the gripping means comprises a gripping surface mounted resiliently between the extreme levels on which at one level it is at a level above one of the cutting blades, and at the other at a level below this same cutting blade during the cutting of the weft thread.

According to still another characteristic feature of the invention, the two cutting blades and the two gripping means are movable, the two cutting blades and one of the gripping means being controlled positively, the other being controlled negatively.

The invention is illustrated by way of non-limitative examples on the adjoining drawings in which:

FIG. 1 is a front view of the device,

FIG. 2 is a view from the right of the FIG. 1, with the cutting blade removed, the holding means being shown in the closed position,

FIG. 3 is a partial view of FIG. 2, the holding means being open,

FIGS. 4, and 6 are sketches representing the holding and the cutting means, respectively in the open position, in the process of closing and in the closed positron,

FIG. 7 is an exploded view showing the elements of the novel weft holder and cutter.

The object of the invention is therefore to provide a device for holding and cutting a weft thread in looms for weaving fabric without a shuttle, until the thread that is held is again taken charge of by the loom, when it moves in the same direction for the passage ofa new weft thread.

A loom for weaving fabric without a shuttle therefore comprises two devices for holding and cutting weft threads similar to that described, these two devices being placed laterally to the woven fabric, close to the areas in which the projectile ends its course, as is known.

A device according to the invention enables the weft thread to be gripped effectively, whatever might be the nature, diameter, degree of torsion, etc... of the latter, without any necessity for accurate adjustment, a delicate task, as is at present necessary for known devices of the same type.

The device thus enables a constant gripping pressure to be exerted on a large gripping surface without deteriorating it, for example by crushing the end of the weft thread, this holding operation being carried out substantially at the same level as that of the normal trajectory of the weft thread as it passes through the shed, so that the weft thread is not excessively displaced laterally between its travel position and the position in which it is held and cut.

The device illustrated on the accompanying drawings consists of a support 1 fixed, for example, on the batten of a loom for weaving fabric, this support being provided with a shaft 2 receiving the two gripping means 3 and 4 which hold the weft thread and the two cutting blades 5 and 6 which cut the weft thread which has just been gripped.

These elements 3, 4, 5 and 6, mounted pivotally on the shaft 2 are held against one another by means of the spring 7 which exerts a pull on the shaft 2. The two gripping means 3 and 4 have surfaces 3, and 4, which are placed parallel to the weft thread 8, so that after pivoting on the shaft 2, they grip the weft thread 8, parallel to its trajectory, as it passes through the shed, that is, without deforming it appreciably which, for certain, would prevent it from being caught by one of the pincer hooks of the projectile.

In addition, as will be described hereafter, one of the gripping means (means 4) is controlled elastically, so that the gripping operation parallel to the trajectory of the thread takes place under constant pressure without any risk of the thread being crushed, whatever may be the nature, the diameter or the degree of torsion of the latterr. It is quite evident that the thread could be held by replacing, for example, the means 4 by a fixed resilient means made of a natural or synthetic material without thereby departing from the scope of the inventron.

In addition, this arrangement allows large gripping surfaces to be obtained ensuring optimum holding strength on account of the presence of the additional deformations, such as 9,, 9 provided on the surfaces 3, or 3,.

The gripping means 3 and 4 and the cutting means 5 and 6 are actuated simultaneously by means of the studs 9 and I0 mounted at the end of the arm 11 pivoting at 12. This arm 11 9is controlled pivotally, at the moment the batten of the loom for weaving fabric reaches the position in which the weft thread beating up operation takes place, by the abutment shown schematically at 13 which bears against the end of the arm II to make it pivot in the direction of the arrow F.

It will be noted, in addition, that stud 9 fits snugly in the recesses in gripping means 3 and cutting blade 5, and stud 10 fits snugly in the recess in cutting blade 6. On the contrary, recess 14 in gripping means 4 is larger in size than stud 10 with which gripping means 4 cooperats, and therefore, stud 10 fits loosely in recess 14 of gripping means 4. Gripping means 4 is constantly pushed by spring blade 15 whch is maintained at 16 by the screw adjustment means 17.

On account of its construction, it is noted that the control of the elements 3, 5 and 6 is positive, whereas the control of the gripping blade 4 is negative and resilient because the stud 10 allows the means 4 to pivot only under the action of the spring blade 15.

In addition, as is seen in FIG. 4, when the gripping means are open, the surface 4, of the means 4 is located at a level above that of the cutting blade 6, this position being determined by the position of the stud 10 on which the gripping means 4 bears under the action of the spring 15 and by the size of recess 14. Thus, when the arm 11 pivots in the direction of the arrow F, there is simultaneous action by stud 9 on gripping means 3 and cutting blade 5 and by stud on cutting blade 6 until the weft thread 8 is held parallel to its length (see FIG. 5) and while the cutting blades 5 and 6 have still not come into contact with one another. As the studs 9 and 10 continue to move, they displace the gripping means 3 and the cutting means 5 and 6, but, at that moment, the gripping means 4 is pushed back by the gripping means 3 against the spring and on account of the play that exists (recess 14) between the means 4 and the stud 10.

During this movement, the gripping force on the weft thread remains therefore substantially constant, while the two cutting blades 5 and 6 cut the weft thread (FIG. 6). It is seen on this Figure, that the gripping means 3 is provided with a recess 3, allowing the various means 3, 5 and 6 to engage in one another without causing any permanent deformation of the weft thread.

When the batten moves again toward the rear and the abutment 13 leaves the arm 11, the latter remains in the closed position on account of the springs 18 placed around the pivot shaft 12 of the arm 11.

The end of the cut weft thread therefore remains held between the means 3 and 4 up to the moment when the projectile, when it moves in the opposite direction, collects the thread held for that purpose by means of its rear pincerhook.

in the extreme rear position of the batten, the lever 11 abuts at 13, to open the blade and the pincer hooks.

The abutment l3, retracting once for every two batten movements, results in the lever 11 being acted upon in the cutting and thread holding position therefore only once every two batten movements.

It will be noted, however, that the gripping means 3 and 4 will not open, in accordance with the operating principles of the device, until after the cutting blades 5 and 6 have opened, that is, after the gripping surface 4, has reached a level above that of the cutting blade 6. This delay in opening by gripping means 3 and 4 occurs because as studs 9 and 10 begin moving to open gripping means 3 and 4 and cutting blades 5 and 6, stud 10 moves out of contact with gripping means 4, and spring 15 exerts sufficient pressure on gripping means 4 to keep gripping means 3 and 4 in contact with each other until cutting blades 5 and 6 separate.

it is obvious that the invention is not limited to the examples of its embodiments herein above described and illustrated and that on the basis of which other methods and other forms of embodiment can be envisaged without departing from the scope of the invention.

What is claimed is:

1. Device for holding and cutting a weft thread for a shuttleless loom, comprising two grippers for holding the weft thread and two cutting blades for cutting the weft thread, said grippers being movably engageable with each other, each of said grippers having a gripping surface which remains parallel to the trajectory of the weft thread in the loom, said grippers and said cutting blades being movably controlled by stud means located in recesses in said grippers and said cuttingg blades, one of said grippers having a recess larger than said stud means to allow substantial relative movement between said gripper and said stud means, and a spring means which contacts and constantly pushes said gripper with the large recess in order to position the gripping area at a level above the area of the cutting blades.

2. Device according to claim 1 wherein said stud means comprises two studs, each of which cooperates with one of said grippers and one of said cutting blades. 

1. Device for holding and cutting a weft thread for a shuttleless loom, comprising two grippers for holding the weft thread and two cutting blades for cutting the weft thread, said grippers being movably engageable with each other, each of said grippers having a gripping surface which remains parallel to the trajectory of the weft thread in the loom, said grippers and said cutting blades being movably controlled by stud means located in recesses in said grippers and said cuttingg blades, one of said grippers having a recess larger than said stud means to allow substantial relative movement between said gripper and said stud means, and a spring means which contacts and constantly pushes said gripper with the large recess in order to position the gripping area at a level above the area of the cutting blades.
 2. Device according to claim 1 wherein said stud means comprises two studs, each of which cooperates with one of said grippers and one of said cutting blades.
 3. Device according to claim 2 wherein said studs are mounted at the end of a pivoting arm.
 4. Device according to claim 1 wherein said gripping surfaces have compLementary irregularities. 